含硼镍基钎料钎焊IC-6合金接头显微组织分析

Study on IC-6 superalloy brazing joint micros tructure with Ni-B filler metal

通过对Ni B钎料在 12 2 0℃保温不同时间钎焊IC 6合金接头显微组织的分析 ,研究了钎缝中γ +γ′组织及近缝区硼化物的形成和变化。结果表明 ,仅依靠母材中Al元素的扩散钎缝中也能形成γ +γ′组织 ,但存在大量晶界 ,对接头高温性能不利。近缝区出现两种类型的硼化物 ,其Ni和Mo原子比分别近似为 1∶ 1和 1∶ 2 ,形貌和分布随保温时间不同而变化。

The brazing joint microstructure of IC 6 superalloy using Ni B alloy at 1220℃ for different heating time was investigated. The results indicate that γ+γ′ can be formed in the brazing seam by the diffusion of Al of IC 6 alloy alone. However, the high temperature stability of γ′ is very poor, and a lot of grain boundaries exist in the brazing seam which are harmful to the joint property. There are two kinds of borides formed in the near seam zone, with different Ni∶Mo (at%).The appearance and distribution of the borides will change for different keeping time at the brazing temperature.